Insulated conductor



Oct. 19, 1937. w. COLVIN, JR

' INSULATED CONDUCTOR Filed July 20, 1934 wsuflrmra (awn/v6 1 3 Ava-0077mm (5177405 GUM/"MAS Patented Oct. 19, 1937 UNITED STATES PATENT OFFICE 2,096,53'i l INSULATED CONDUCTOR William Colvin, In, Troy; N. Y. Application July 20, 1934, Serial No. 736,275

12 Claim.

10 referred to, to improve the construction and insulation of such conductors, and to provide an improved insulating medium that while possessing high dielectric properties and capable of withstanding a high degree of heat, is relatively thin, is flexible, hard and tough and will not crack or be separated by abrasion, whereby a more durable, eihcient, satisfactory conductor is afforded that can be produced at low cost.

The invention, with other objects and advantages thereof, will be understood from the hereinafter contained detail description, when considered in connection with the accompanying drawing, forming part hereof and illustrating two forms of my improved conductor.

In the drawing:

Figure l is a side elevation of a portion of a conductor constructed in accordance with the present invention.

Fig. 2 is a greatly magnified drawing of the 30 conductor.

Fig. 3 is a cross section of the same.

Fig. 4 is a side view of a-portion of one of the wires. v

Fig. '5 is a side elevation of a portion of a slightly modified construction.

Fig. 6 is a cross section of the construction illustrated in Figure5.

The invention comprehends a conductor formed of a number of fine, highly flexible wires 40 enamel, the small insulated wire elements being twisted together and the twisted group or assemblage having aflexible insulating coating of enamel. In the particular exemplification of my improved conductor illustratedin Figures 1 to 4 of the drawing, the conductor is made up 'of copper wires, a group of twelve #32 wires (B and S gauge) being shown. l designates the wires each of which is provided with a'relatively thin, 5 flexible, insulating coating of enamel 2. As

shown the small insulated wireelements i are twisted together and thetwisted groupof wires has a relatively thin,fie'xible coating of enamel 3. The invention contemplates the use, in some Manganese resinate drier each having a flexible insulating coating of instances, of one or more strengthening wires with a group of fine copper wires. The strengthening wire or wires may be of soft iron or any other suitable metal or alloy. Such a construction is illustrated in Figures'fi and 6. The construction here shown comprises twelve copper wires #34 (B and S gauge) designated 4 and one strengthening wire (B and S gauge) of soft iron designated 6, the latter like each of the copper wires having a thin flexible coating of enamel. 5 designates the insulating coating of the copper wires and 1 theinsulating coating of the strengthening wire. The strengthening wire and the copper wires are twisted together and the asemblage of insulated wires is provided with a flexiblecoating of enamel 8.

'In accordance with the present invention, an insulating coating or lacquer for the individual wires and for the twisted group of wires is provided, the same comprising rosin ester and China wood oil with lead drier, manganese resinate drier, and kerosene as a thinner. Instead of lead drier and manganese resinate drier, other equivalent driers may be employed, and other thinning agents may be used in place of kerosene. The following is an example of the proportions in which the difierent ingredients are used in the coating mixture:

White rosin ester 120 China wood oil 240 14 Lead linoleate 8 Kerosene 360 In the preparation of the rosin ester, 600 parts of white rosin is melted and heated to 400 F. -35 for a few minutes. 72 parts of glycerine is then slowly added, care being taken to not allow the liquid mass to foam over. The temperature is then raised to 550 F. and after this temperature has been maintained forabout twenty minutes, 3 parts of good powdered quick lime is added to complete the reaction between the rosin and glycerine, and the heating continued for about ten minutes.

' In manufacturing the coating or lacquer, the white rosin ester is heated to about 480 F. The China wood oil is added gradually over a period Y of twenty minutes, never allowing the temperature to drop below 460 F. and after all the oil has been added, the heatingis continued for another ten minutes at 480 F. The temperature isthen lowered to 450 F. The lead linoleate and the manganese resinate drier are then added and the temperature of 450 F. maintained for about thirty minutes, after whichfthe temperature is reduced around 390 F. and the kerosene gradually added with stirring, the mixture being permitted to cool after the stirring in of the kerosene.

To the coatingmixture or lacquer thus produced, the proper amount ofbenzol or any naptha solvent is added as a thinner.

The insulating coating mixture or lacquer is applied to the wire from which the individual conductor elements are formed and to the twisted group of insulated wires by successive passes through a bath and baking oven. For instance, the wire may be given a multiple number of coats of lacquer, and the twisted assemblage of insulated wires may be given a multiple number of coats. After each coat, the wire is passed to suitable wiping means which acts to smooth out the enamel on the wire; remove any surplus enamel, and toinsure uniform thickness of the coating. The wire is then run through a suitable oven at a temperature of from 500 F. to 700 F., and

at a speed of sixty to eighty feet per minute depending somewhat on the size of the wire being coated. The thickness of the coating may vary from say 0.00015 to 0.0005 of an inch depending upon the size of the wire. The same procedure is followed in applying the coating to the twisted group or assemblage of wires except that in this instance the successive coats are baked on at gradually reduced heats 'to prevent over baking of the inner layers or coats of enamel. The film or coating of enamel prepared in this way possesses high dielectric strength and is capable of withstanding a high degree of heat. The enamel has the characteristic of being a heat conductor so that heat generated by passing current through the wire is quickly dissipated. It

is impervious to moisture, is extremely flexible, is

hard andtough, and will not crack or separate by abrasion.

By theparticular construction and the special coating mixture and process hereinbefore set forth, a conductor of .a highly eiflcient, satisfactory nature is afforded. The necessity for textile insulating coverings such as cotton, silk, etc., as:

in the construction of cord My improved conductor is very durable, the insulating coating commonly employed conductors is entirely avoided.

of the'same while highly flexible being tough and hard and strongly resistant to abrasion, and these qualities coupled with its smoothness also make it advantageous in the installation of'house wiring systems in threading the conductor through in walls.

what I claim is:

1. As a new article of manufacture, an electrical conductor of the cord type adapted for use in house wiring or electric fixtures where extreme flexibility is required, comprising a number of fine highly flexible wires twisted together, each individual wire having a flexible insulating coating of enamel, and the twisted-assemblage of wires having a flexible insulating coating of enamel, the whole being flexible to substantially any extent and in substantially any direction desired while characteristim of hardtoughness; resistance to, cracking or ness, abrasion, and proof against moisture.

2.Asanewarticleofmanufacture,anelec-' triealconductor ofthe cord typeadaptedforuse in house wiring or electric fixtures where extreme flexibility h required, comprising a number of finehlghlyflexibiewirestwistedtogetheneach' individual wir'e having a flexible insulating layers of enamel and the twisted assemblage of wires having a flexible insulating coating consisting of a plurality of baked on layers of enamel, the whole being flexible to substantially any extent and in substantially any direction desired while possessing characteristics of hardness, toughness, resistance to cracking or abrasion,

'and proof against moisture.

3. As a new article of manufacture, an electrical conductor of the cord type adapted for use in house wiring or electric fixtures where extreme flexibility is required, comprising a number of fine copper wires and one or more flne strengthening wires'of a metal of greater tensile strength than copper twisted together, each individual wire having a flexible coating of enamel,

and the twisted assemblage of wires having a flexible coating of enamel, the whole being flex ible to substantially any extent and in substantially any direction desired while possessing characteristics of hardness, toughness, resistance to cracking or abrasion, and proof against moisture.

4. As a new article of manufacture, an elecance to cracking or abrasion, and proof against.

moisture.

5. As a new article of manufacture, an electrical conductor of the cord type adapted for use in house wiring or electric fixtures where extreme flexibilityis required, comprising a number of fine highly flexible wires twisted together, each individualwire and the twisted assemblage of wires having flexible baked on coatings of. amixture includingChinawoodoll, rosin ester, athinning agent and lead drier, the whole being flexible to inhousewiringorelectrlcfixtureswhereextreme is required, comprisim a num- Mancunian-lath! nf Innin- Tl toughness, resistance to cracking or abrasion,

and proof against moisture.

8. As a new article of manufacture, an electrical conductor of the cord type adapted for usein house wiring or electric fixtures whereextreme flexibility is required, comprising a num-- ber of fine highly flexible wires'twisted together,

' each individual wire and the twisted assemblage of wires having flexible baked on coatings'containing China wood oil, rosin and glycerine, the whole being flexible to substantially any extent and in substantially any direction desired while possessing characteristics of hardness, toughness, resistance to cracking or abrasion, and proof against moisture.

9. As a new article of manufacture, an electrical conductor of the cord type adapted for use in house wiring or electric fixtures where'ex-' ness, toughness, resistance to cracking or abrasion, and proof against moisture.

10. As a new article of manufacture, an electrical conductor of the cord type adapted for use in house wiring or electric fixtures where extreme flexibility is required, comprising a number of fine highly flexible wires twisted together, each individual wire and the twisted assemblage of wires having flexible baked on coatings containing white rosin, glycerine, China wood oil, a thinning agent, lead drier, and manganese resinate drier, the whole being flexible to substantially any extent and in substantially any'direction desired while possessing characteristics of hardness, toughness, resistance to cracking or abrasion, and proof against moisture.

11. As a new article of manufacture, an electrieal conductor of the cord type adapted for use inhouse wiring or electric fixtures where extreme flexibility is required; comprising a number of fine highly flexible wires twisted together, each individual wire and the twisted assemblage of wires having a flexible baked on coating of a mixture of approximately 240 parts China wood oil, parts rosin ester, 360 parts of a thinning agent, and 22 parts of a drying agent, the whole being flexible to substantially any extent and in substantially any direction desired whilepossessing the characteristics of hardness, toughness, resistance to cracking or abrasion, and proof against moisture.

12. As a new article of manufacture, an electrical conductor of the cord type adapted for use in house wiring or electric fixtures where extreme flexibility is required, comprising a number of line highly flexible wires twisted together, each individual wire and the twisted assemblage of istics of hardness, toughness, resistance to cracking or abrasion, and proof against moisture. WILLIAM COLVIN, JR. 

